<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */

/**
 * Converts to and from JSON format.
 *
 * JSON (JavaScript Object Notation) is a lightweight data-interchange
 * format. It is easy for humans to read and write. It is easy for machines
 * to parse and generate. It is based on a subset of the JavaScript
 * Programming Language, Standard ECMA-262 3rd Edition - December 1999.
 * This feature can also be found in  Python. JSON is a text format that is
 * completely language independent but uses conventions that are familiar
 * to programmers of the C-family of languages, including C, C++, C#, Java,
 * JavaScript, Perl, TCL, and many others. These properties make JSON an
 * ideal data-interchange language.
 *
 * This package provides a simple encoder and decoder for JSON notation. It
 * is intended for use with client-side Javascript applications that make
 * use of HTTPRequest to perform server communication functions - data can
 * be encoded into JSON notation for use in a client-side javascript, or
 * decoded from incoming Javascript requests. JSON format is native to
 * Javascript, and can be directly eval()'ed with no further parsing
 * overhead
 *
 * All strings should be in ASCII or UTF-8 format!
 *
 * LICENSE: Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met: Redistributions of source code must retain the
 * above copyright notice, this list of conditions and the following
 * disclaimer. Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
 * NO EVENT SHALL CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * @category
 * @package     Services_JSON
 * @author      Michal Migurski <mike-json@teczno.com>
 * @author      Matt Knapp <mdknapp[at]gmail[dot]com>
 * @author      Brett Stimmerman <brettstimmerman[at]gmail[dot]com>
 * @copyright   2005 Michal Migurski
 * @version     CVS: $Id: JSON.php,v 1.31 2006/06/28 05:54:17 migurski Exp $
 * @license     http://www.opensource.org/licenses/bsd-license.php
 * @link        http://pear.php.net/pepr/pepr-proposal-show.php?id=198
 */

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_SLICE',   1);

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_IN_STR',  2);

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_IN_ARR',  3);

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_IN_OBJ',  4);

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_IN_CMT', 5);

/**
 * Behavior switch for Services_JSON::decode()
 */
define('SERVICES_JSON_LOOSE_TYPE', 16);

/**
 * Behavior switch for Services_JSON::decode()
 */
define('SERVICES_JSON_SUPPRESS_ERRORS', 32);

/**
 * Converts to and from JSON format.
 *
 * Brief example of use:
 *
 * <code>
 * // create a new instance of Services_JSON
 * $json = new Services_JSON();
 *
 * // convert a complexe value to JSON notation, and send it to the browser
 * $value = array('foo', 'bar', array(1, 2, 'baz'), array(3, array(4)));
 * $output = $json->encode($value);
 *
 * print($output);
 * // prints: ["foo","bar",[1,2,"baz"],[3,[4]]]
 *
 * // accept incoming POST data, assumed to be in JSON notation
 * $input = file_get_contents('php://input', 1000000);
 * $value = $json->decode($input);
 * </code>
 */
class Services_JSON
{
    /**
     * constructs a new JSON instance
     *
     * @param    int     $use    object behavior flags; combine with boolean-OR
     *
     *                           possible values:
     *                           - SERVICES_JSON_LOOSE_TYPE:  loose typing.
     *                                   "{...}" syntax creates associative arrays
     *                                   instead of objects in decode().
     *                           - SERVICES_JSON_SUPPRESS_ERRORS:  error suppression.
     *                                   Values which can't be encoded (e.g. resources)
     *                                   appear as NULL instead of throwing errors.
     *                                   By default, a deeply-nested resource will
     *                                   bubble up with an error, so all return values
     *                                   from encode() should be checked with isError()
     */
    function Services_JSON($use = 0)
    {
        $this->use = $use;
    }

    /**
     * convert a string from one UTF-16 char to one UTF-8 char
     *
     * Normally should be handled by mb_convert_encoding, but
     * provides a slower PHP-only method for installations
     * that lack the multibye string extension.
     *
     * @param    string  $utf16  UTF-16 character
     * @return   string  UTF-8 character
     * @access   private
     */
    function utf162utf8($utf16)
    {
        // oh please oh please oh please oh please oh please
        if(function_exists('mb_convert_encoding')) {
            return mb_convert_encoding($utf16, 'UTF-8', 'UTF-16');
        }

        $bytes = (ord($utf16{0}) << 8) | ord($utf16{1});

        switch(true) {
        case ((0x7F & $bytes) == $bytes):
            // this case should never be reached, because we are in ASCII range
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(0x7F & $bytes);

        case (0x07FF & $bytes) == $bytes:
            // return a 2-byte UTF-8 character
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(0xC0 | (($bytes >> 6) & 0x1F))
                . chr(0x80 | ($bytes & 0x3F));

        case (0xFFFF & $bytes) == $bytes:
            // return a 3-byte UTF-8 character
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(0xE0 | (($bytes >> 12) & 0x0F))
                . chr(0x80 | (($bytes >> 6) & 0x3F))
                . chr(0x80 | ($bytes & 0x3F));
        }

        // ignoring UTF-32 for now, sorry
        return '';
    }

    /**
     * convert a string from one UTF-8 char to one UTF-16 char
     *
     * Normally should be handled by mb_convert_encoding, but
     * provides a slower PHP-only method for installations
     * that lack the multibye string extension.
     *
     * @param    string  $utf8   UTF-8 character
     * @return   string  UTF-16 character
     * @access   private
     */
    function utf82utf16($utf8)
    {
        // oh please oh please oh please oh please oh please
        if(function_exists('mb_convert_encoding')) {
            return mb_convert_encoding($utf8, 'UTF-16', 'UTF-8');
        }

        switch(strlen($utf8)) {
        case 1:
            // this case should never be reached, because we are in ASCII range
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return $utf8;

        case 2:
            // return a UTF-16 character from a 2-byte UTF-8 char
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(0x07 & (ord($utf8{0}) >> 2))
                . chr((0xC0 & (ord($utf8{0}) << 6))
                | (0x3F & ord($utf8{1})));

        case 3:
            // return a UTF-16 character from a 3-byte UTF-8 char
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr((0xF0 & (ord($utf8{0}) << 4))
                | (0x0F & (ord($utf8{1}) >> 2)))
                    . chr((0xC0 & (ord($utf8{1}) << 6))
                        | (0x7F & ord($utf8{2})));
        }

        // ignoring UTF-32 for now, sorry
        return '';
    }

    /**
     * encodes an arbitrary variable into JSON format
     *
     * @param    mixed   $var    any number, boolean, string, array, or object to be encoded.
     *                           see argument 1 to Services_JSON() above for array-parsing behavior.
     *                           if var is a strng, note that encode() always expects it
     *                           to be in ASCII or UTF-8 format!
     *
     * @return   mixed   JSON string representation of input var or an error if a problem occurs
     * @access   public
     */
    function encode($var,$formatted = false)
    {
        if ($formatted) {
            return $this->json_format($var);
        }
        switch (gettype($var)) {
        case 'boolean':
            return $var ? 'true' : 'false';

        case 'NULL':
            return 'null';

        case 'integer':
            return (int) $var;

        case 'double':
        case 'float':
            return (float) $var;

        case 'string':
            // STRINGS ARE EXPECTED TO BE IN ASCII OR UTF-8 FORMAT
            $ascii = '';
            $strlen_var = strlen($var);

            /*
             * Iterate over every character in the string,
             * escaping with a slash or encoding to UTF-8 where necessary
             */
            for ($c = 0; $c < $strlen_var; ++$c) {

                $ord_var_c = ord($var{$c});

                switch (true) {
                case $ord_var_c == 0x08:
                    $ascii .= '\b';
                    break;
                case $ord_var_c == 0x09:
                    $ascii .= '\t';
                    break;
                case $ord_var_c == 0x0A:
                    $ascii .= '\n';
                    break;
                case $ord_var_c == 0x0C:
                    $ascii .= '\f';
                    break;
                case $ord_var_c == 0x0D:
                    $ascii .= '\r';
                    break;

                case $ord_var_c == 0x22:
                    //forward slash:  commented out so as not to escape 'em:
                //case $ord_var_c == 0x2F:
                case $ord_var_c == 0x5C:
                    // double quote, slash, slosh
                    $ascii .= '\\'.$var{$c};
                    break;

                case (($ord_var_c >= 0x20) && ($ord_var_c <= 0x7F)):
                    // characters U-00000000 - U-0000007F (same as ASCII)
                    $ascii .= $var{$c};
                    break;

                case (($ord_var_c & 0xE0) == 0xC0):
                    // characters U-00000080 - U-000007FF, mask 110XXXXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack('C*', $ord_var_c, ord($var{$c + 1}));
                    $c += 1;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;

                case (($ord_var_c & 0xF0) == 0xE0):
                    // characters U-00000800 - U-0000FFFF, mask 1110XXXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack('C*', $ord_var_c,
                        ord($var{$c + 1}),
                        ord($var{$c + 2}));
                    $c += 2;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;

                case (($ord_var_c & 0xF8) == 0xF0):
                    // characters U-00010000 - U-001FFFFF, mask 11110XXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack('C*', $ord_var_c,
                        ord($var{$c + 1}),
                        ord($var{$c + 2}),
                        ord($var{$c + 3}));
                    $c += 3;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;

                case (($ord_var_c & 0xFC) == 0xF8):
                    // characters U-00200000 - U-03FFFFFF, mask 111110XX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack('C*', $ord_var_c,
                        ord($var{$c + 1}),
                        ord($var{$c + 2}),
                        ord($var{$c + 3}),
                        ord($var{$c + 4}));
                    $c += 4;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;

                case (($ord_var_c & 0xFE) == 0xFC):
                    // characters U-04000000 - U-7FFFFFFF, mask 1111110X
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack('C*', $ord_var_c,
                        ord($var{$c + 1}),
                        ord($var{$c + 2}),
                        ord($var{$c + 3}),
                        ord($var{$c + 4}),
                        ord($var{$c + 5}));
                    $c += 5;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;
                }
            }

            return '"'.$ascii.'"';

        case 'array':
            /*
             * As per JSON spec if any array key is not an integer
             * we must treat the the whole array as an object. We
             * also try to catch a sparsely populated associative
             * array with numeric keys here because some JS engines
             * will create an array with empty indexes up to
             * max_index which can cause memory issues and because
             * the keys, which may be relevant, will be remapped
             * otherwise.
             *
             * As per the ECMA and JSON specification an object may
             * have any string as a property. Unfortunately due to
             * a hole in the ECMA specification if the key is a
             * ECMA reserved word or starts with a digit the
             * parameter is only accessible using ECMAScript's
             * bracket notation.
             */

            // treat as a JSON object
            if (is_array($var) && count($var) && (array_keys($var) !== range(0, sizeof($var) - 1))) {
                $properties = array_map(array($this, 'name_value'),
                    array_keys($var),
                    array_values($var));

                foreach($properties as $property) {
                    if(Services_JSON::isError($property)) {
                        return $property;
                    }
                }

                return '{' . join(',', $properties) . '}';
            }

            // treat it like a regular array
            $elements = array_map(array($this, 'encode'), $var);

            foreach($elements as $element) {
                if(Services_JSON::isError($element)) {
                    return $element;
                }
            }

            return '[' . join(',', $elements) . ']';

        case 'object':
            $vars = get_object_vars($var);

            $properties = array_map(array($this, 'name_value'),
                array_keys($vars),
                array_values($vars));

            foreach($properties as $property) {
                if(Services_JSON::isError($property)) {
                    return $property;
                }
            }

            return '{' . join(',', $properties) . '}';

        default:
            return ($this->use & SERVICES_JSON_SUPPRESS_ERRORS)
                ? 'null'
                : new Services_JSON_Error(gettype($var)." can not be encoded as JSON string");
        }
    }

    /**
     * array-walking function for use in generating JSON-formatted name-value pairs
     *
     * @param    string  $name   name of key to use
     * @param    mixed   $value  reference to an array element to be encoded
     *
     * @return   string  JSON-formatted name-value pair, like '"name":value'
     * @access   private
     */
    function name_value($name, $value)
    {
        $encoded_value = $this->encode($value);

        if(Services_JSON::isError($encoded_value)) {
            return $encoded_value;
        }

        return $this->encode(strval($name)) . ':' . $encoded_value;
    }

    /**
     * reduce a string by removing leading and trailing comments and whitespace
     *
     * @param    $str    string      string value to strip of comments and whitespace
     *
     * @return   string  string value stripped of comments and whitespace
     * @access   private
     */
    function reduce_string($str)
    {
        $str = preg_replace(array(

            // eliminate single line comments in '// ...' form
            '#^\s*//(.+)$#m',

            // eliminate multi-line comments in '/* ... */' form, at start of string
            '#^\s*/\*(.+)\*/#Us',

            // eliminate multi-line comments in '/* ... */' form, at end of string
            '#/\*(.+)\*/\s*$#Us'

        ), '', $str);

        // eliminate extraneous space
        return trim($str);
    }

    /**
     * decodes a JSON string into appropriate variable
     *
     * @param    string  $str    JSON-formatted string
     *
     * @return   mixed   number, boolean, string, array, or object
     *                   corresponding to given JSON input string.
     *                   See argument 1 to Services_JSON() above for object-output behavior.
     *                   Note that decode() always returns strings
     *                   in ASCII or UTF-8 format!
     * @access   public
     */
    function decode($str)
    {
        $str = $this->reduce_string($str);

        switch (strtolower($str)) {
        case 'true':
            return true;

        case 'false':
            return false;

        case 'null':
            return null;

        default:
            $m = array();

            if (is_numeric($str)) {
                // Lookie-loo, it's a number

                // This would work on its own, but I'm trying to be
                // good about returning integers where appropriate:
                // return (float)$str;

                // Return float or int, as appropriate
                return ((float)$str == (integer)$str)
                    ? (integer)$str
                    : (float)$str;

            } elseif (preg_match('/^("|\').*(\1)$/s', $str, $m) && $m[1] == $m[2]) {
                // STRINGS RETURNED IN UTF-8 FORMAT
                $delim = substr($str, 0, 1);
                $chrs = substr($str, 1, -1);
                $utf8 = '';
                $strlen_chrs = strlen($chrs);

                for ($c = 0; $c < $strlen_chrs; ++$c) {

                    $substr_chrs_c_2 = substr($chrs, $c, 2);
                    $ord_chrs_c = ord($chrs{$c});

                    switch (true) {
                    case $substr_chrs_c_2 == '\b':
                        $utf8 .= chr(0x08);
                        ++$c;
                        break;
                    case $substr_chrs_c_2 == '\t':
                        $utf8 .= chr(0x09);
                        ++$c;
                        break;
                    case $substr_chrs_c_2 == '\n':
                        $utf8 .= chr(0x0A);
                        ++$c;
                        break;
                    case $substr_chrs_c_2 == '\f':
                        $utf8 .= chr(0x0C);
                        ++$c;
                        break;
                    case $substr_chrs_c_2 == '\r':
                        $utf8 .= chr(0x0D);
                        ++$c;
                        break;

                    case $substr_chrs_c_2 == '\\"':
                    case $substr_chrs_c_2 == '\\\'':
                    case $substr_chrs_c_2 == '\\\\':
                    case $substr_chrs_c_2 == '\\/':
                        if (($delim == '"' && $substr_chrs_c_2 != '\\\'') ||
                            ($delim == "'" && $substr_chrs_c_2 != '\\"')) {
                                $utf8 .= $chrs{++$c};
                            }
                        break;

                    case preg_match('/\\\u[0-9A-F]{4}/i', substr($chrs, $c, 6)):
                        // single, escaped unicode character
                        $utf16 = chr(hexdec(substr($chrs, ($c + 2), 2)))
                            . chr(hexdec(substr($chrs, ($c + 4), 2)));
                        $utf8 .= $this->utf162utf8($utf16);
                        $c += 5;
                        break;

                    case ($ord_chrs_c >= 0x20) && ($ord_chrs_c <= 0x7F):
                        $utf8 .= $chrs{$c};
                        break;

                    case ($ord_chrs_c & 0xE0) == 0xC0:
                        // characters U-00000080 - U-000007FF, mask 110XXXXX
                        //see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 2);
                        ++$c;
                        break;

                    case ($ord_chrs_c & 0xF0) == 0xE0:
                        // characters U-00000800 - U-0000FFFF, mask 1110XXXX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 3);
                        $c += 2;
                        break;

                    case ($ord_chrs_c & 0xF8) == 0xF0:
                        // characters U-00010000 - U-001FFFFF, mask 11110XXX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 4);
                        $c += 3;
                        break;

                    case ($ord_chrs_c & 0xFC) == 0xF8:
                        // characters U-00200000 - U-03FFFFFF, mask 111110XX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 5);
                        $c += 4;
                        break;

                    case ($ord_chrs_c & 0xFE) == 0xFC:
                        // characters U-04000000 - U-7FFFFFFF, mask 1111110X
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 6);
                        $c += 5;
                        break;

                    }

                }

                return $utf8;

            } elseif (preg_match('/^\[.*\]$/s', $str) || preg_match('/^\{.*\}$/s', $str)) {
                // array, or object notation

                if ($str{0} == '[') {
                    $stk = array(SERVICES_JSON_IN_ARR);
                    $arr = array();
                } else {
                    if ($this->use & SERVICES_JSON_LOOSE_TYPE) {
                        $stk = array(SERVICES_JSON_IN_OBJ);
                        $obj = array();
                    } else {
                        $stk = array(SERVICES_JSON_IN_OBJ);
                        $obj = new stdClass();
                    }
                }

                array_push($stk, array('what'  => SERVICES_JSON_SLICE,
                    'where' => 0,
                    'delim' => false));

                $chrs = substr($str, 1, -1);
                $chrs = $this->reduce_string($chrs);

                if ($chrs == '') {
                    if (reset($stk) == SERVICES_JSON_IN_ARR) {
                        return $arr;

                    } else {
                        return $obj;

                    }
                }

                //print("\nparsing {$chrs}\n");

                $strlen_chrs = strlen($chrs);

                for ($c = 0; $c <= $strlen_chrs; ++$c) {

                    $top = end($stk);
                    $substr_chrs_c_2 = substr($chrs, $c, 2);

                    if (($c == $strlen_chrs) || (($chrs{$c} == ',') && ($top['what'] == SERVICES_JSON_SLICE))) {
                        // found a comma that is not inside a string, array, etc.,
                        // OR we've reached the end of the character list
                        $slice = substr($chrs, $top['where'], ($c - $top['where']));
                        array_push($stk, array('what' => SERVICES_JSON_SLICE, 'where' => ($c + 1), 'delim' => false));
                        //print("Found split at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");

                        if (reset($stk) == SERVICES_JSON_IN_ARR) {
                            // we are in an array, so just push an element onto the stack
                            array_push($arr, $this->decode($slice));

                        } elseif (reset($stk) == SERVICES_JSON_IN_OBJ) {
                            // we are in an object, so figure
                            // out the property name and set an
                            // element in an associative array,
                            // for now
                            $parts = array();

                            if (preg_match('/^\s*(["\'].*[^\\\]["\'])\s*:\s*(\S.*),?$/Uis', $slice, $parts)) {
                                // "name":value pair
                                $key = $this->decode($parts[1]);
                                $val = $this->decode($parts[2]);

                                if ($this->use & SERVICES_JSON_LOOSE_TYPE) {
                                    $obj[$key] = $val;
                                } else {
                                    $obj->$key = $val;
                                }
                            } elseif (preg_match('/^\s*(\w+)\s*:\s*(\S.*),?$/Uis', $slice, $parts)) {
                                // name:value pair, where name is unquoted
                                $key = $parts[1];
                                $val = $this->decode($parts[2]);

                                if ($this->use & SERVICES_JSON_LOOSE_TYPE) {
                                    $obj[$key] = $val;
                                } else {
                                    $obj->$key = $val;
                                }
                            }

                        }

                    } elseif ((($chrs{$c} == '"') || ($chrs{$c} == "'")) && ($top['what'] != SERVICES_JSON_IN_STR)) {
                        // found a quote, and we are not inside a string
                        array_push($stk, array('what' => SERVICES_JSON_IN_STR, 'where' => $c, 'delim' => $chrs{$c}));
                        //print("Found start of string at {$c}\n");

                    } elseif (($chrs{$c} == $top['delim']) &&
                        ($top['what'] == SERVICES_JSON_IN_STR) &&
                            ((strlen(substr($chrs, 0, $c)) - strlen(rtrim(substr($chrs, 0, $c), '\\'))) % 2 != 1)) {
                                // found a quote, we're in a string, and it's not escaped
                                // we know that it's not escaped becase there is _not_ an
                                // odd number of backslashes at the end of the string so far
                                array_pop($stk);
                                //print("Found end of string at {$c}: ".substr($chrs, $top['where'], (1 + 1 + $c - $top['where']))."\n");

                            } elseif (($chrs{$c} == '[') &&
                                in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))) {
                                    // found a left-bracket, and we are in an array, object, or slice
                                    array_push($stk, array('what' => SERVICES_JSON_IN_ARR, 'where' => $c, 'delim' => false));
                                    //print("Found start of array at {$c}\n");

                                } elseif (($chrs{$c} == ']') && ($top['what'] == SERVICES_JSON_IN_ARR)) {
                                    // found a right-bracket, and we're in an array
                                    array_pop($stk);
                                    //print("Found end of array at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");

                                } elseif (($chrs{$c} == '{') &&
                                    in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))) {
                                        // found a left-brace, and we are in an array, object, or slice
                                        array_push($stk, array('what' => SERVICES_JSON_IN_OBJ, 'where' => $c, 'delim' => false));
                                        //print("Found start of object at {$c}\n");

                                    } elseif (($chrs{$c} == '}') && ($top['what'] == SERVICES_JSON_IN_OBJ)) {
                                        // found a right-brace, and we're in an object
                                        array_pop($stk);
                                        //print("Found end of object at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");

                                    } elseif (($substr_chrs_c_2 == '/*') &&
                                        in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))) {
                                            // found a comment start, and we are in an array, object, or slice
                                            array_push($stk, array('what' => SERVICES_JSON_IN_CMT, 'where' => $c, 'delim' => false));
                                            $c++;
                                            //print("Found start of comment at {$c}\n");

                                        } elseif (($substr_chrs_c_2 == '*/') && ($top['what'] == SERVICES_JSON_IN_CMT)) {
                                            // found a comment end, and we're in one now
                                            array_pop($stk);
                                            $c++;

                                            for ($i = $top['where']; $i <= $c; ++$i)
                                                $chrs = substr_replace($chrs, ' ', $i, 1);

                                            //print("Found end of comment at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");

                                        }

                }

                if (reset($stk) == SERVICES_JSON_IN_ARR) {
                    return $arr;

                } elseif (reset($stk) == SERVICES_JSON_IN_OBJ) {
                    return $obj;

                }

            }
        }
    }

    function isError($data, $code = null)
    {
        if (is_object($data) && (get_class($data) == 'services_json_error' ||
            is_subclass_of($data, 'services_json_error'))) {
                return true;
            }
        return false;
    }


//added by PK from http://us2.php.net/json_encode
    function json_format($data)
    {
        $tab = "  ";
        $new_json = "";
        $indent_level = 0;
        $in_string = false;

        $json = $this->encode($data);
        $len = strlen($json);

        for($c = 0; $c < $len; $c++)
        {
            $char = $json[$c];
            switch($char)
            {
            case '{':
            case '[':
                if(!$in_string)
                {
                    $new_json .= $char . "\n" . str_repeat($tab, $indent_level+1);
                    $indent_level++;
                }
                else
                {
                    $new_json .= $char;
                }
                break;
            case '}':
            case ']':
                if(!$in_string)
                {
                    $indent_level--;
                    $new_json .= "\n" . str_repeat($tab, $indent_level) . $char;
                }
                else
                {
                    $new_json .= $char;
                }
                break;
            case ',':
                if(!$in_string)
                {
                    $new_json .= ",\n" . str_repeat($tab, $indent_level);
                }
                else
                {
                    $new_json .= $char;
                }
                break;
            case ':':
                if(!$in_string)
                {
                    $new_json .= ": ";
                }
                else
                {
                    $new_json .= $char;
                }
                break;
            case '"':
                if($c > 0 && $json[$c-1] != '\\')
                {
                    $in_string = !$in_string;
                }
            default:
                $new_json .= $char;
                break;                   
            }
        }
        return $new_json;
    }

}

class Services_JSON_Error
{
    function Services_JSON_Error($message = 'unknown error', $code = null,
        $mode = null, $options = null, $userinfo = null)
    {

    }
}

